The California Academy of Sciences is a natural history museum located in San Francisco, California. It is one of the largest and most visited museums of its kind in the world, housing over 26 million specimens and artifacts across its various exhibits.

The museum's exhibits are divided into four main areas: the Steinhart Aquarium, which houses over 40,000 live animals and plants from around the world; the Kimball Natural History Museum, which displays a variety of specimens and dioramas representing the earth's natural history; the Morrison Planetarium, which features a 75-foot-diameter dome projecting stunning visual and audio shows about the universe; and the Osher Rainforest, which houses a four-story tropical rainforest with free-flying birds and butterflies.

The California Academy of Sciences is also home to the Institute for Biodiversity Science and Sustainability, which conducts research and supports initiatives aimed at promoting conservation and sustainability around the world. In addition, the museum hosts a variety of educational programs and events for visitors of all ages, including lectures, workshops, and classes.

The California Academy of Sciences has won numerous awards for its sustainable design, including the Platinum LEED Certification, and has been recognized as one of the greenest museums in the world.